1. Field of the Invention
The present invention relates to shape memory alloy heat engines and more particularly to a nitinol wire powered vertically oscillating heat engine.
2. Description of the Prior Art
The inventor of the present invention is also the inventor of the Banks Engine, U.S. Pat. No. 3,913,326, for Energy Conversion System, issued Oct. 21, 1975, which employed bent wires and was the first proven reliable nitinol powered engine. The "Background Of The Invention" section of that patent sets forth in part the status of the prior art at the time of that invention. The "Summary Of The Invention" section of that patent describes the thermodynamic working material, which powers the engine, as a thermally responsive memory material, such as nitinol. The same material is used to power the present invention. The thermally responsive materials which demonstrate these thermal response characteristics have come to be known as the shape memory effect class of materials.
Subsequent to the development of the original engine, the inventor developed an improved engine to extract the tensile energy of straight nitinol wire. That engine is disclosed in the U.S. Pat. No. 4,257,231, for Heat Engine, issued Mar. 24, 1981. "The Background Of The Invention" section of that patent sets forth in part the status of the prior art which had developed to the time of that invention. The "Summary Of The Invention" section of that patent describes the problems with extracting energy from straight wires of nitinol or any other thermally responsive shape memory effect material.
In March of 1983, the inventor filed a patent application on a single wire nitinol engine which demonstrated a much lighter and simpler construction than had been known for providing an operable nitinol engine. That application issued as U.S. Pat. No. 4,450,686 on May 29, 1984.
In February of 1985, the inventor filed an application for a linear output nitinol engine which overcame the problems of extracting usable energy from the heat engine disclosed in U.S. Pat. No. 4,257,231. The application resulted in U.S. Pat. No. 4,563,876 for a Linear Output Nitinol Engine, issued Jan. 14, 1986. The "Summary Of The Invention" section of that patent sets forth three particular areas of design in which improvements were disclosed in the patent.
The disclosures of the above referenced patents are incorporated herein by reference for a more complete understanding of the present invention. Additional basic wire powered mechanisms have now been conceived for extracting energy from shape memory materials such as nitinol, and one of these mechanisms is described by the present disclosure. Another wire powered engine is described in the disclosure filed concurrently herewith.